Screens for receiving optical images, particularly for advertising purposes are already known, and these screens are made by surfaces fixedly or movably mounted within cylindrical or spherical volumes.
Actually French Pat. No. 70-44060 (publication No. 2,116,789) discloses a screen forming surface mounted within a cylindrical volume, this screen being transparent and receiving directly or through a set of mirrors an image coming from a projector in order to exhibit an enlarged image on the screen.
French certificate of addition No. 74-10774 (publication No. 2,266,249) shows a translucent screen mounted within a sphere. The screen is of a circular shape, rotates on itself and receives from a projector an image which, because the screen rotates, begins with a given magnitude, extends, contracts and then disappears.
In the two above mentioned disclosures, the images are obtained from transparencies, but it is also possible to use other elements such as camera films with a discontinuous feeding.
Yet, all the above embodiments are not satisfactory since the projection of these images in volumes, although it is attractive, is nevertheless not very visible, more particularly when placed in full daylight or in well lighted rooms.
Besides, the apparatus made until now are bulky and do not enable practical arrangements, for example, by suspending the screen in its housing at a certain distance from the projector.